Improvement in door-springs



" z. an. B. coBB.

DOOR-SPRINGS.

' No."194',511. Panentea'Augyzs.,1s77.

UNITED STATES. PATENT OFFICE.`

ZENAS COBB AND HENRY B. COBB, OF WILMINGTON, DELAWARE.

IMPRlOVEMEN-T IN DOCR-SPRINGS.

Specification' forming part of Letters Patent No. 194,511, dated August28, 1877 application lled July 31, 1876. i

To all whom 'it may concern:

Be it known that we, ZENAS COBB and HEN- RY B. COBB, of Wilmington, inthe county of New Castle and State of Delaware, have invented a new andImproved Door-Spring; and we do hereby declare the following to be afull and exact description of the same, reference being had to theaccompanying drawings, forming part of this specification, in whichyFigure 1 is a perspective view of the spring applied to a door. Fig. 2is an edge view, showing the position of the spring when the door isfully opened. Fig. 3 is a longitudinal section. Fig. 4 is a perspectiveview of one of the spring-leaves; 'and Fig. 5 is a perspective view,showing a double-leaf instead of a single-leaf spring.

Similar letters ot' reference in the accompanying drawings denotethesame parts.

Our invention has for its object to improve the construction andoperation ofdoor-springs, that they shall be more eflicient and durablethan those commonly employed.

To this end the invention consists, first, in constructing the spring ofseveral thin steel leaves, which are so attached to their fastenings, byVmeans substantially as described, that when the door is opened theleaves shall slide freely upon each other, and be compressed in the formof a reverse curve, for the purpose of increasing the .force of thespring; and, second, in the novel construction ot' the clasp and bracketby which the spring is attached to the door and door-jamb.

In. the accompanying drawings, A is the spring, composed of a number ofthin steel strips or leaves placed together, and attached at oppositeends to a bracket, B, and clasp C. The ends of the leaves are slottedlongitudinally for the passage of screws D, by which they are attachedto the bracket and clasp. The bracket is secured to the central rail ofa door, E, as shown in Fig. 1, and the clasp is hinged to the outer endof a curved arm, F, projecting outward from the door-jamb. This armprojects farther to the front of the door `than the bracket B, and holdsthe spring in a line curved slightly in opposite directions, so thatwhen the door is swung lopen the spring shall be compressed in reversecurves, as

shown in Fig. 2, for the purpose of increasing its force to move thedoor and hold it closed. The double curvature shortens the length ofeach curve, and therefore imparts greater force to the spring undercompression than it could possibly possess if arranged to form a singlearc or curve from end to end. The slotted ends of the springs permitthem to move or slide freely upon each other, so that they shall operateindependently without spring` ing apart. Lugs or side pieces g g on thebracket and clasp serve to guide the ends of the springs, and preventthem from turning on the screws D.

The ends h h of the bracket and clasp, over which the spring bends whenthe door is opened,are curved outward away from the spring, as shown, toform broad guiding-sun faces for it to bend over, instead 4of sharpedges, which would be liable to break the spring if the door wereVopened quickly.

The arm F curves back somewhat away from the door for the purpose ofallowing the spring to be carried back upon the door-jamb to hold thedoor open. 1

A door-spring composed of a series of sliding leaves is powerful enoughto close any door to which it maybe applied, and elastic enough to yieldreadily and uniformly when the door is opened. It' a single thick springwere used, it would either break or remainpermanently bent whencompressed by the opening door, while a single thin spring would be tooweak to effect any purpose whatever.

Instead of employing one series of springs, two may be used, placed sideby side, as shown in Fig. 5, in whibhcase thebracket and clasp are madea little wider, and have partitionsfour in each-to properly separate thetwo series of springs.

Having thus described our invention, what we claim is y 1. A door-springcomposed of a series of thin steel leaves, which are each attached tosuituable supports at both their ends, by means substantially asdescribed, and adapted to slide freely upon each other throughout theirentire length when the door is opened and blosed.

2. The door-spring composed of a series of thin steel leaves, attachedat both their ends to supports upon a door and its jemb, all the 4. Thebracket B and clasp C, each proleaves sliding freely upon each other,and vided with a curved end, h, substantially as each compressed inreverse curves When the described. door is opened, substantially asdescribed, for the purpose specified. ZENAS COBB.

3. ThebracketB,hiugedclaspO, and curved HENRY B. COBB. erm F, combinedwith the springA, composed of a. series of thin steel leaves adapted toslide Witnesses: upon eachother, substantially as described. v M. J.REID, for the purpose specied. l B. G. HILDRETH.

